In an ink jet recording head, as in JP-A-2003-159795, a plurality of pressure chambers disposed in two arrays is provided in a cavity unit in which a plurality of plates is stacked, and an actuator including energy generators (in JP-A-2003-159795, activators) corresponding to the pressure chambers is bonded to the cavity unit. Then, in order to apply a voltage to the energy generators of the actuator, surface electrodes corresponding to the energy generators are provided, on a top surface of the actuator, along both longitudinal side edges thereof, and bonding terminals of a wiring material and terminals of the actuator are bonded to be superimposed on each other. The wiring material being formed to be long in a longitudinal extension direction of the actuator, a large number of wires connected to two arrays of the bonding terminals in the longitudinal direction are formed in a portion of narrow width (a width in a direction perpendicular to the longitudinal direction) of the wiring material, and extended to an exterior, and the wires from the bonding terminals have a minute width and a narrow distance between them.
In JP-A-11-147311, it is considered that a flexible wiring material (in JP-A-11-147311, a flexible circuit substrate), being configured of a stacked body of a plurality of substrate layers each including wires on one surface, has an opening formed in at least one of the plurality of substrate layers, in which bonding electrodes are formed by exposing via the opening the wires of a substrate layer disposed on a rear side of the at least one substrate layer, and bonded to surface electrodes used as discrete electrodes, thereby realizing a high integration of the wires.
Also, in JP-A-2005-161760, in a configuration of the flexible wiring material (in JP-A-2005-161760, a flexible flat cable), a plurality of discrete bonding electrodes electrically connected independently to a plurality of energy generators which emit an energy for causing an ink ejection to an actuator is staggered and stepped, thereby preventing a distance between the wires from being too small in a place having high wiring density.